package com.itheima.reggie.common;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.ser.std.ToStringSerializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalDateTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.deser.LocalTimeDeserializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalDateTimeSerializer;
import com.fasterxml.jackson.datatype.jsr310.ser.LocalTimeSerializer;
import java.math.BigInteger;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import static com.fasterxml.jackson.databind.DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES;


/*  对象映射器:基于jackson将Java对象转为json，或者将json转为Java对象
  将JSON解析为Java对象的过程称为 [从JSON反序列化Java对象]
  从Java对象生成JSON的过程称为 [序列化Java对象到JSON]
  */
public class JacksonObjectMapper extends ObjectMapper {

    public static final String DEFAULT_DATE_FORMAT = "yyyy-MM-dd";
    public static final String DEFAULT_DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";
    public static final String DEFAULT_TIME_FORMAT = "HH:mm:ss";

    public JacksonObjectMapper() {
        super();
        //收到未知属性时不报异常
        this.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);

        //反序列化时，属性不存在的兼容处理
        this.getDeserializationConfig().withoutFeatures(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);


        SimpleModule simpleModule = new SimpleModule()
                .addDeserializer(LocalDateTime.class, new LocalDateTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addDeserializer(LocalDate.class, new LocalDateDeserializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addDeserializer(LocalTime.class, new LocalTimeDeserializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)))

                .addSerializer(BigInteger.class, ToStringSerializer.instance)
                .addSerializer(Long.class, ToStringSerializer.instance)

                .addSerializer(LocalDateTime.class, new LocalDateTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_TIME_FORMAT)))
                .addSerializer(LocalDate.class, new LocalDateSerializer(DateTimeFormatter.ofPattern(DEFAULT_DATE_FORMAT)))
                .addSerializer(LocalTime.class, new LocalTimeSerializer(DateTimeFormatter.ofPattern(DEFAULT_TIME_FORMAT)));

        //注册功能模块 例如，可以添加自定义序列化器和反序列化器
        this.registerModule(simpleModule);


        //在长整型bigint转换成java的long类型时会造成精度缺失,所以需要这一个通用的配置类来转换,
        //本质上时将json转换成java语言,将较大的数字转换成响应的字符串:.addSerializer(BigInteger.class, ToStringSerializer.instance)
        //                                                  .addSerializer(Long.class, ToStringSerializer.instance)
        //需要配置一个配置类: @Override
        //    protected void extendMessageConverters(List<HttpMessageConverter<?>> converters) {
        //        log.info("扩展消息转换器...");
        //        //创建消息转换器对象
        //        MappingJackson2HttpMessageConverter messageConverter = new MappingJackson2HttpMessageConverter();
        //        //设置对象转换器，底层使用Jackson将Java对象转为json
        //        JacksonObjectMapper jacksonObjectMapper = new JacksonObjectMapper();
        //        messageConverter.setObjectMapper(jacksonObjectMapper);
        //        //将上面的消息转换器对象追加到mvc框架的转换器集合中
        //        converters.add(0,messageConverter);
        //重写extendMessageConverters方法
    }
}
